Alarm circuit



Aug. 28, 1928. 1,682,049

- J. F. MEYERS ALARM CIRCUIT Filed Oct. 13, 1924 ZZZ/5277.47"?- PatentedAug. 28, 1928 UNITED STATES 1,682,049 PATENT OFFICE.

JOHN F. MEYERS, OF CHICAGO, ILLINOIS, ASSIGNOR T0 KELLOGG SWITCHBOARDAND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINGIS.

ALARM CIRCUIT.

Application filed October 13. 1824.

My invention relates to ringing interrupt ers, such as are commonly usedin connection with ringing and signaling means in telephone exchangesystems. In telephone systoms of the class in which so-called automaticor machine ringing is employed, duplicate ringing interrupters areemployed, one which may be termed the primary ringing interrupter, whichis motor-driven. The current for operating the motor is usually suppliedfrom a 110 volt circuit received from an outside source, such as thetown or city electric power plant. The other ringinginterrupter is alsomotor-driven and the current for operating the motor is supplied bycurrent received from an exchange storage battery. In many instances thesource of current operating the motor for rotating the interruptermechanism of the primary interrupter is shut off, which makes itnecessary to employ the emer gency ringing interrupter, and in order toconnect the storage battery with the motor for rotating the emergencyinterrupter mech anism, the operator presses a button which is locatedon the switchboard and under her control, or a switch, which is locatedon the power board.

In many cases the operator is unaware of the stopping of the interruptermechanism, and my invention is a means of giving an immediate alarm wheneither the primary interrupter or the emergency interrupter fails tofunction properly, stopping on either an open or a closed contact, orwhen any of the interrupter leads become grounded for any reasonwhatsoever.

In the accompanying drawing the preferred form of my invention is shownat A.

It consists of eight slow-acting relays, namely, relays 1 to 8,inclusive, and two quickaeting relays, namely, relays 9 and 10, and asuitable alarm device 11.

At B is shown the primary ringing interrupter consisting of a shaft arevolving at a predetermined speed. To the rotatable shaft of theprimary ringing interrupter are secured disks, 7), c, d and 0, each ofwhich is provided with a cam surface f, the purpose of which is to closecontacts for completing interrupter circuits. l

. At G is the emergency ringing interrupter composed of a rotating shaft(1 to which are secured disks Z), c, d and 6. each disk having acam 7,the purpose of which is to close contacts for completing interruptercircuits.

Serial No. 743,237.

To further illustrate my invention I have shown a portion of a cordcircuit D, for connecting the ringing current controlled by the ringinginterrupters B and C with a sub scribers station E. The cord circuit Dis designed for automatic ringing, and I have shown the ringinginterrupters B and C in position to be operated therewith. The cordcircuit consists of a calling plug P, a calling ,supervisory relay US, asupervisory lamp SS and the apparatus necessary for automatic ringing.This consists of a party-line ringing key BK, four ringing generators G,G, G and G a ringing control relay BCR, an interrupter relay IR, and aswitch relay SW. The subscribers station E terminates in a line circuitL, which consists of a line relay LR, a cut-off relay G0, a line signalS, and multiple jacks J. l I

The motor driven ringing interrupters are connected by means ofdouble-throw knife switches 23, 23, 23" and 23, to the interrupter leadsI, I, I and I which are distributed to the different cord circuits inthe diifcrent operators positions in the exchange.

The following is a description of the action of my invention inconnection with the ringing interrupters B and C. The action is the sameinboth cases. that is, if the primary ringing interrupter B is connectedto the interrupter leads by means of the double-throw knife switches,the action of A and D will be the same as it would be if the emergencyringing interrupter C was connected to the interrupter leads by means ofthe doublethrow knife switches, V

F or purposes of illustration, we will assume that theprimary ringinginterrupter B is in operation. I will describe the action of disk Z),the action of disks 0, (Z and e being'similar to that of disk I). I Whenthe cam f engages with spring contact 12, it presses contact 12 intoengagement with contact 13 which energizes the ringing interrupter relayin the cord circuit D, in the usual. manner, and also energizes relay 10in A by current flow ing from battery through the lower winding of relay10, conductor 22, interrupter lead through switch 23, spring contact 12contact 13 and conductor 24 to ground. This circuit will remain closedas long as cam f on disk 7) is riding over and pressing spring contact12 into engagement with contact 13, or it will remain closed when cam fon disk 0 is riding over and pressing spring contact 12' into engagementwith contact 13. herefore, relay 10 is energized whenever cams f ondisks 7) or are pressing spring contacts 12 01 12' into engagement withcontacts 13 or 13, and relay 9 is energized. whenever cams f on disks dor e are pressing spring contacts 12 or 12 into engagement with contacts13 or 13 Relay 9 has the same effect as relay 10 on the slow-actingrelays, namely relays 1 to 8, inclusive, all of which may be readilyunderstood by one skilled in the art.

.Vhen the ringing interrupter B is in operation, the alarm signal 11,will not be operated because of the l ollowing action: When rotatingshaft a revolves, cam f on disk 7) presses spring contact 12intoengagement with contact 13, this action energizes relay 10, setting up acircuit as before described. hen relay 10 is energized, it attractsarmature 25 which energizes relay 5 by means of current flowing frombattery through conductor h, relay 5, conductor 9, alternate contact 25of relay to ground. The actuation of relay 9 has the same effecton relay5, as has the actuation of relay 10, because when relay 9 is actuated itestablishes a circuit for the energization of relay 5 by current flowingfrom battery through conductor h, relay 5, conductors g and If to groundat alternate contact 36 of relay 9. The actuation of rela 5 energizesrela 6 b r the establishment of a circuit in this manner, currentflowing from battery, through conductor h. relay 6, conductor is.alternate contact 26, which was attracted when relay 5 was energized andconductor j to ground. By this action relay 7 is actuated by currentflowing from battery' through conductor h, relay 7, conductor Z, al.-ternate contact 27, and conductor 7' to ground. Relay 8 is actuated andattracts its armature, by current flowing from battery throngh conductork, relay 8, conductor m, alternate contact 28, and conductor j toground.

When relay 8 attracts its armature 29, ground is removed from thecircuit of the alarm device, shown in the accompanying drawing in theform of a bell 11. This prevents the bell from ringing, provided relay 4is-actuated and its armature 34 is attracted. Cam f, on disk 5, pressesspring contact 12 into engagement with contact 13 for one second andreleases it for four seconds.

When camf on disk B passes spring contact 12, the circuit for theenergization of relay 1O 1s broken and relay 10 1s ole-energized, thus-=its armature 31 is attracted. and a circuit is closed throiwh relay" 2by current flowing from battery through conductor h, relay 2,

conductor p, alternate contact 31 and conductor 7' to ground. 7 Relay 2is thus energized and closes a circuit for relay 3, current flowrelay 4,are in their alternate positions, and

the groundfor the completion of a circuit through the alarm devicemust'come through -either armature 29 when itis inits normal position,or through armature 34 when it is in its normal position.

VVheu relay 10 was (lo-energized armature returned to its normalposition, thus breaking the circuit for the energization of relay byremoving ground. Relay 5, being a slowacting relay, does not release itsarmature immediately, but hesitates fora traction of a second. When itdoes release, its armature 26, the armature returns to its normalposition, thus breaking the circuit for the energization of relay 6.Relay 6, when de-energized, releases its armature 27 which breaks thecircuit for the eneiigization of relay 7. When relay 7 releases itsarmature 28, the circuit for the energization of relay 8 is broken.Before it can release its armature, due to the delay caused by theslow-action oi" relays 5, 6 and 7, a new circuit for the energization ofthe relays has been set up by the next diskon the rotating shaft of theringing interrupter pressing spring contact 12 into engagement-withcontact 13. Each succeeding disk on the rotatable shaft o'f'the ringinginterrupter sets up a circuit in the relays and thus the relays i and 8are constantly energized and their armatures attracted as long as theringing interrupter is working.

It will be noted that the energizing circuits for the lower group ofslow-acting relays eluding relays 5, 6, 7 "an d 8 are controlled by themake contacts 25 and 36 of relays 10 and 9 8 respectively, whiletheenergizationcircuit of the upper group of relays including relays 1,2, 3 and 4 are controlled by the back contacts and 30 of relays 10 and 9respectively. Belay 10 is energized each time'disks Z) and 0 close theircontacts while relay 9 is energized each time disks (Z and 6 close theirassoc'ated contacts. it will'thus be seen that relays9 and 10 follow thegrounding of the interrupter leads l, I; I and The slowacting relays areso timed that when the interrupter machines are operating at theirnormal speed the last relays of the series, 4 and 8 do not de-energizeto close the alarm circuit before they again have their circuits closedby the preceding slow-acting relays of the series.

I will neX describe how an alarm will be given if the-ringinginterrupter stops working when on an open circuit. If the ringinginterrupter stops on an open circuit none of the cams f, on the disks7), 0, (Z and 6, will be pressing spring contacts 12, 12, 12 and 12 andconsequently there will not be a ground connection on any of theinterrupter leads I, I, I and I If the interrupter leads I, I, I and Ihave no ground connection, relays 9 and 10 cannot be energized,'and ifrelays 9 and 10 cannot be energized, relays 5, 6, 7 and 8 will bede-energized, thus allowing armature 29 of relay 8 to resume its normalposition which will set up a circuit in the alarm device 11, by currentflowing from battery through conductor 7;, bell11, conductor a, andalternate contact 29 to ground. When the bell 11 is operated, an alarmis given informing the operator that the ringing interrupter in use hasstopped working.

I will next give a description of the action when the ringinginterrupter stops on a closed contact. I will say for an illustrationthat the ringing interrupter stops when cam f on disk I) is pressingspring contact 12 into engagement with contact 13, thus energizing relay10 by establishing acircuit as follows: battery through relay 10,conductor 22, interrupter lead I, switch 23, spring contact 12,

contact 13 and conductor 24 to ground. hen relay 10 is energized, itattracts the armature 35 which breaks the circuit for energizing re lay1 by taking ground off it. hen relay 1 is deenergized, it releases thearmature 31 which breaks the circuit for energization of .-relay 2,which in turn breaks the circuit for the energization of relay 3, andthe d e-energization of relay 3 breaks the circuit for the actuation ofrelay 4, which returns its armature 34 to its normal position which willcause the bell 11 to operate togive an alarm, current flowing frombattery through conductor 72/, bell 11, conductor 8, normal contact 34and conductor to ground, all of which will be understood by oneskilled'in the art.

If one of the interrupter leads should become permanently groundedeither relay 9 or 10 will remain steadily energized in which event oneof the series of slow-acting relays will become ole-energized and closea circuit for alarm device 11. I

It will likewise be noted that if one or more of the interruptercontacts should fail to connect ground to an interrupter lead that thealarm device will be operated. This may occur due to dirty contacts ordue to the springs failing to properly contact.

I will next describe the action of the ringing interrupters B and C 1ncon]unction wlth the cord circuit D, assuming that D is one of the cordcircuits to which interrupter lead I is common. Assuming that theoperator desires to signal the subscriber at E, she inserts plug P intojack J, closing an energizing circuit for the cut-01f relay CO, andswitching relay SIV, in series, current flowing from battery through thewinding of relay SIV, sleeve contacts of plug P and 'ack J, the windingof relay CO to ground. 'lhe relay SW closes its alternate contact 40,closing a circuit for the supervisory signal SS which remains lighteduntil the called subscriber answers. The operator now fully depressesthe proper ringing key plunger P, P P or P, of the partyline ringing keyRK, and assuming it is the plunger P which is depressed, the end springs15 and 16 momentarily assume their alternate positions, the spring 16closing an energizing circuit for the ringing control relay RCR, tracedfrom battery through relay RCR, conductor 14, alternate contact 16,conductor 37, normal contact 38, conductor 39 and alternate contact 40of relay SIV to ground. Although the circuit oi relay RCR is interruptedat contact 16, when the operator removes pressure from the actuatedplunger, the relay RGR closes a locking circuit for itself, traced frombattery through relay RCR, alternate contact 41, conductor 42, normalcontact 38, conductor 39 and alternate contact 40 of relay SW to ground.

Upon the energization of relay RCR, its altern-ate contact 17 is closed,which connects interrupter lead I of the ringing interrupter with theinterrupter relay IR of the cord circuit D. Assuming that the cam 7 ondisk I) of the ringing interrupter is pressing spring contact 12 intoengagement with contact 13, an energizing circuit for the interrupterrelay IR is established, traced from battery through winding of relayIR, conductor 44, normal contact 15, conductor 43, alternate contact 17,conductor 18, and interrupter lead I, switch 23, spring contact 12,contact 13 and conductor 24 to ground. Upon the energization of relay IRit closes its alternate contact 45 which connects ringing current to thecalled line from the ungrounded pole of the generator G, alternatecontact 2 2, conductor 52, alternate contact 45, conductor 51, alternatecontact 53, conductor 50, tip contacts of the plug P and jack J,alternate contact 54 of relay ()0, conductor 49, through the subscribersset at E, conductor 48, alternate contact 55, sleeve contacts of jack Jand plug P, conductor47, alternate contact 46, of relay IR to batteryand ground. The interrupter relay IR is energized each time theinterrupter lead I is connected to ground through action of disk 6 oncontacts 12 and 13 of the ringing interrupter, thus connecting ringingcurrent to the wanted line for about one second of time, and allowing asilent interval of about four seconds which are the intervals of the camf on the disk I), engaging and disengaging with spring contact 12 of theringing interrupter.

-lVhen the called subscriber answers an v energizing circuit l-or relayCb 1s set up,

traced from ground through relay CS, nor- 'mal contact 45, which wasreleased when ground was taken oil interrupter lead l, as was explainedpreviously, through conductor 51, alternate contact 53 of relay SW,conductor 50, tip contacts of plug P and jack J, alternate contact 54 ofrelay ()0, conductor 49, subscribers set E, conduct-or l8, alternatecontact 55 of relay GO, sleeve cont-act of jack J and plug P, andwinding of relay Sl V, to battery. When the relay CS is energized itsnormal contact 38 is opened, this breaks the locking circuit for relayEUR, which de-energiz s and opens the circuit of relay IR at itsalternate contact 17. The opening of the alternate contact '17disconnects the lead I which prevents the relay IR from again operating.The opening or alternate contact 38 of relay CS efiaces the lamp signalSS. Nhen conversation has been completed, the subscriber again placeshis receiver on the hook switch and relay CS is de=energized, thuslighting signal SS, whereupon the operator withdraws the plug P from thejack J, restoring'the cord and line circuits.

While I have illustrated my invention in connection with a mechanicalinterrupter and with a cord circuit, I do not wish thereby to be limitedto this particular application of my invention, as it may be used for anumber of purposes.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. An alarm system for ringing interrupters comprising in combination,an alarm, an alarm circuit, means for maintaining the alarm circuit openduring the normal operation of the interrupter comprising a train ofquick-pick-up-slow-releasc relays, means whereby the first relay of thetrain is energized periodically by the interrupter, means whereby theenergization of each of the remaining relays is controlled by itspreceding relay independently of the interrupter and means whereby thedeenergization of the last relay in the train closes the alarm circuit,the number of relays and their period of release being such that thelast relay of the train will not be deenergized between successiveclosures of the circuit of the first relay by the interrupter.

2. An alarm system for ringing inter rupters comprising in combination,an alarm and an alarm circuit therefor, means for maintaining the alarmcircuit open duringnormal operation of the interrupter comprising quickacting and a train of slow release relays, means whereby the quickacting relays are actuated by the interrupter, means whereby the quickacting relays control the cnergization of the train of slow releaserelays, and means whereby the deenergization ot the last relay in thesaid train of relays closes the said alarm circuit.

3. An alarm system {or ringing interruptcrs coi'nprising in combination,an alarm and an alarm circuit therefor, means for controlling the alarmcircuit including a series of relays, means whereby the first or theseries oi. relays is controlled periodically by the interrupter, meanswhereby the energization of each of the remaining relays is controlledby its preceding relay independently of the interrupter,means wherebythe normal operation of the relays by the interrupter maintain the saidalarm circuit open, and means whereby it the interrupter fails tooperate the relays of said train of relays the said alarm circuit isclosed and the said alarm lays of said series 01 relays operated saidalarm circuit will be closed.

5. An alarm system for ringing interrupters comprising in combination,an alarm, an alarm circuit, means for maintaining the alarm circuit openduring the normal operation of the interrupter comprising quick and aseries of slow actingrelays, means whereby the quick acting relays areenergized periodically by the interrupter.

means whereby the energization of the firs slow acting relays iscontrolled by the said quick acting relays and the energization of eachof the remaining relays is controlled by ts preceding relayindependently of the interrupter, and means whereby anoperation of oneof the relays of said series closes the alarmcircnit, the number ofrelays of said series of relays and their period of operation being suchthat the said relay will close the said alarm circuit for an incorrectoperation or said interrupter.

Signed by me at Chicago, in the county of Cook, and State of Illinois,this 10th day of October, 1924.

Jonur. MEYERS.

